Imaging devices are used in many different applications in industry and medicine. For example, an endoscope is an instrument that includes an elongated thin shaft that may be inserted into a cavity to obtain an image from the cavity. Early endoscopes included a light transmission element or arrangement to transmit an image from a distal end of the shaft to an eyepiece of the instrument. Rather than transmitting the light image itself from the distal end of the shaft to an eyepiece, many modern endoscopes employ an electronic imaging device at the distal end of the shaft. The imaging device receives an image from the distal end of the shaft and converts the image to electrical signals. These electrical signals are communicated the length of the shaft to processing elements which ultimately use the signals to generate a signal for driving a display device to reproduce the image received at the distal end of the shaft.
The electronic imaging device employed by the more modern approach includes an image sensing module along with an arrangement of one or more lenses which introduce an image to the image sensing module. The image sensing module includes an image sensor and electronic components which must be located in close proximity to the image sensor. One or more printed circuit boards (referred to hereafter simply as “circuit boards”), provide mounting points for the image senor and electronic components, and also provide connecting points for wires which provide power and wires which are used to carry the electrical signals from the distal end of the shaft to the signal processing and display driving components of the endoscope.
It is desirable for the shaft of an endoscope to be readily flexible along its entire length to facilitate placement of the shaft distal end at a desired location within a cavity. However, the electronic imaging device employed in modern endoscopes is essentially a rigid element. Thus where an electronic imaging device is used, the length of the shaft which covers the imaging device does not have the desired flexibility. It is therefore desirable to reduce the overall length of the imaging device.
One way to reduce the overall length of an imaging device is to reduce the length of the image sensor module included in the device. However, the image sensor module must still include the necessary elements and provide room for the various electrical connections between elements.